The present invention relates to a display control method and display control apparatus for a layout image to display, for example, an image to be printed.
Generally, photographs taken by a digital camera are stored in a memory card as image data. Some printers read image data directly from the memory card and print the read image data without intervention of a personal computer. At the time of printing image data stored in a memory card using this type of printer, the memory card is inserted into a card slot of the printer. Then, image data to be printed is selected and the number of prints to be made is designated both through the operation panel of the printer, after which initiation of printing is instructed through the operation panel. The operation panel has a liquid crystal display section and a plurality of operation keys. By operating the operation keys while viewing the liquid crystal display section, a user selects image data to be printed, set the number of prints to be made and instruct the initiation of printing.
Another type of printer has a monitor (color liquid crystal display) capable of displaying an image to be printed or a print status image. This type of printer can allow a user to check the print status before printing without using a personal computer.
Recent digital cameras have the capability to store print attribute information in a memory card in addition to image data. The print attribute information includes the number of prints, the type and size of a sheet to be used in printing, and a layout to be adopted at the time of printing. The print attribute information is reflected on a print status image which is displayed on the monitor.
In the case where three pieces of image data are to be printed on a single sheet, for example, three print status images 81 based respectively on the three pieces of image data are displayed on a monitor screen 80 in the same layout as the layout included in the attribute information, as shown in FIG. 18. To display the print status images 81 on the screen 80, a preview display switch provided on the operation panel is to be depressed.
In general, the processing speed of a CPU (Central Processing Unit) which is used in a printer is however slower than the processing speed of a CPU which is used in a personal computer. It therefore normally takes several seconds (e.g., two to three seconds) for the print status images 81 to be displayed since the depression of the preview display switch. Even in the case where a user wants to check only the layout of the print status images 81, therefore, the user cannot give an instruction for another process until the display of the print status images 81 is completed.
In addition, every operation of the operation panel is disabled while the display of the print status images 81 is completed after the depression of the preview display switch. Even if the preview display switch is depressed erroneously, therefore, the user cannot instruct another process until the display of the print status images 81 is completed.
Japanese Laid-Open Patent Publication No. 10-79913 (pages 11 to 14 and FIGS. 31 and 32) discloses a method for displaying the thumb-nail image of a real image before displaying the actual image. The amount of data on a thumb-nail image is smaller than the amount of data on a real image. Therefore, the time needed to display a thumbnail image is shorter than the time needed to display a real image. This method can permit a user to check the layout of a real image, without waiting for the display of the real image to complete, at the point when the display of its thumb-nail image is completed. However, the time needed to display a thumb-nail image (about 0.5 second) is not short enough though shorter than the time needed to display a real image. That is, the user cannot check the layout of a real image in so short a time.